I'm using [the ECVerify library](https://gist.github.com/axic/5b33912c6f61ae6fd96d6c4a47afde6d) and in the test examples in that contract, `function ecverify(bytes32 hash, bytes sig, address signer) returns (bool) {}` expects `bytes sig` in the format `"\xFF\xFF\xFF..."`, and it does not seem to work with a `bytes sig = "0xFFFFFF..."` format.

How do I convert `bytes32 sig = 0xaca7da997ad177f040240cdccf6905b71ab16b74434388c3a72f34fd25d6439346b2bac274ff29b48b3ea6e2d04c1336eaceafda3c53ab483fc3ff12fac3ebf200` to `bytes sig = "\xac\xa7\xda...`?